# small sample size with Likert data

I have 5 point Likert scale answers to questions and I want to compare the results for 2 practice types. I have only 17 respondents from one type so I believe my best approach is the Fisher exact test.

The articles I can find that do something like this seem to just look at the responses for agree & strongly agree. I'm assuming they must be running the test with # A/SA responses and the number of all other responses (neutral, disagree and strongly disagree). So if there are 2 categories, they have a 2x2 matrix of data they are testing for each question.

On the one hand it seems like you'd want to you all of the data you have an not condense it down so much. On the other hand, by doing that you're making it easier to reach significance because you're distinguishing between all of the Likert values, where you weren't before. And this test doesn't understand that the data is ordinal, which means you're losing information.

Are these simply limitations of what I can do with this data? Should I use the 2x2 matrix of data or the 5x2 data (all of the detail)?

Thank you!

• Any reason, not to use a Mann-Whitney U or Wilcoxon test? May 14, 2018 at 14:38
• Welcome to CV! On this site there's no need to say "thank you" at the end of your post - it might seem rude at first, but it's part of the philosophy of this site (tour) to "Ask questions, get answers, no distractions" and it means future readers of your question don't need to read through the pleasantries. May 14, 2018 at 15:11
• Regarding those other tests, don't they require that the distrib and variance of the 2 be the same? For some of my answers, they are not, just by inspection. The answers are clustered more heavily at the end of the Likert scale for one practice type than the other. May 14, 2018 at 19:35
• [My comments got long, so I converted to answer.] May 15, 2018 at 14:57